Expander for sealing rings



Dc. 11, 192s.

1,694,566 D. M. SOLENBERGER EXPANDER Fon sEALING RINGS Filed Dec. 31, V19:25

Patented Dec. 11, 1928.

UNITED STATES PATENT OFFICE.

DEAN M. SOLENBERGER, OF CLEVELAND, OHIO, ASSIGNOR TO SIMPLEX PISTON RING COMPANY, 'OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

` EXPANDER FOR SEALING RINGS.

Application led December 6 tures.

normally high temperatures.

It is the object of the invention to provide a means for conforming the ring to the surface of the cylinder in all portions of the piston travel and even Where the cylinder is distorted or of varying diameter in different portions.

It is a further object to eliminate piston slap such as occasioned by the angularity of the connecting Arod and Where the 'piston does not closely fit the cylinder.

Still further it is an object to obtain a construction which will maintain its eiiiciency after long service or Where subjected to ablV ith these objects in view the invention consists in the peculiar construction of resilient expander through which a distributed radial pressure is applied to the piston ring as hereinafter set forth.

In the drawings;

Figure l is a horizontal section through a piston and cylinder.

Figure 2 is a section online 2-2 of Figure l.

Figure 3 is a plan vieW of the expande detached. l

Figure 4 is a horizontal section through the piston and ring showing the, expander in 4 fully expanded condition.

Figure 5 is a similar view showing the piston and ring in engagement with the cylinder and the expander under tension.

Figure 6 is a diagram illustrating the modification in form of the expander to vary the tension thereof.

A is a cylinder; B a piston having one or more grooves C therein for receiving the sealing rings D. These rings are preferably limited in radial thickness so as to be extremely flexible and consequently have insufficient tension in themselves to maintain proper peripheral sealing contact. This is particularly true, if as shpwn, the rings are circumferentially slotted and are compressed to exert a resilient tension upon the side Walls of the groove. It is therefore necessary to applyl additional radial pressure which is accomplished by an expander of the following construction; E is a ribbon preferably formed of steel and of a Width which Will loosely fit 31, 1925. Serial No. 78,678.

ed contacts with the inner face of the ring D and intermediate contacts with the bottom face of the ring groove. All of these bends vare of a predetermined selected radius and thereverse curves are connected by straight line portions tangent thereto. Thus, variations in the tension of the expander'may be obtained either by changing the radius of the bends or by increasing or diminishing the number of corrugations. By such variations any desired radial pressure may be applied to the ring Within the ring groove to produce the desiredI pressure of the ring against the cylinder. Also with this form of construction practically all of the metal of the ribbon is at Work and localized stresses which might 4weaken theex'pander or cause a permanent set thereof are avoided.

As is Well understood, the elastic limit of the metal is determined `by the heat treatment, being greatest Where the temper is drawn to theleast extent. Inasmuch how-x ever, as the expander is subjected to theinternal heat of the engine, any temper which is drawn less than theftemperature to which the ribbon may be subsequently subjected, will not be permanent. Therefore, an expander which would properly function when first installed, might later prove ineffectual due to the drawing of the temper thereof. I have avoided this diiiculty by drawing the temper of the ribbon of which the expander is formed, by a temperature in excess of the maximum temperature to which it may subsequently be subjected in the engine. This limits the permissible degree of deflectiony but by varying the distance between successive contacting bearings and by placing all or the greater part of the metal at Work, the proper degree of expansion may be obtained iWithin the elastic limit. Also byl using the expander in combination With rings abnormally thin radially, suiiicient clearance is provided in a ring roove which is designed for receiving a sing e piece ring.

Figures 4 and 5 show the expander respectively in fully expanded position and in compressed position. In the former, the reverse curves E and E2 are of their natural radius and are connected by a straight portion Es tangent thereto.

In Figure 5 the curves E and E2 have been iiattened out to some extent against the consion of the expander and therefore any de-v sired tension may be obtained by the selection of a proper radius. The tension may also be varied by increasing or decreasing the number of corrugations in the ring.

The construction of expander above described is useful not only in maintaining contact of the rin with the cylinder but 1n resisting piston s ap against the cylinder walls. The tension required for these combined functions may be determined and the requisite variation produced for diferent constructions by varying the number of corrugations in the circle of the ribbon.

What I claim asmy invention is:

1. An expander for a sealing ring comprising a resilient ribbon corrugated to form a series of reverse curves and intermediate portions tangent thereto, the radii of said curves being selected to produce in the oper? ation ofthe expander a predetermined radial pressure.

2. An expander for a sealing ring`r comprising a resilient ribbon corrugated to form a series of spaced reverse curves having radii selected to produce in the operation of the expander a predetermined radial pressure, and intermediate portions tangent to said curves inversely variable to the radii thereof to maintain a substantially constant spacing between centers of curves.

3. An expander for alsealingv ringin an internal combustion engine comprising a corrugated tempered steel ribbon having its temper drawn by a temperature in excess to a maximum temperature to which said eX- pander is subjected in the engine, said corrugations forming in series of reverse curves of selected radii and intermediate portions tangent to said curves. inversely variable to the radii thereof to maintain a substantially constant spacing between centers of curves. Intestimony whereof I aiiix my signature.

' DEAN M. SOLENBERGER. 

